Cellular telephones are well known in the art. A cellular telephone is defined as a handheld computer, embedded controller, or embedded controller that includes a system unit having a central processing unit (CPU) and associated volatile and non-volatile memory. The cellular telephone may also include random access memory (RAM), basic input/output system read only memory (BIOS ROM), an attached LCD display touch screen, a pointing device to enter text (stylus), serial ports, parallel ports, infrared ports, a wireless modem, analog-to-digital converters (ADC), digital-to-analog converters (DAC), or CODEC devices for connecting to the public telephone switched network. One of the distinguishing characteristics about cellular telephones is that the components are sufficiently small and modular to allow them to fit on a system board that fits into the user's hand and is powered by batteries.
Cellular telephones can receive input from either an internal microphone or an external microphone connected to the cellular telephone through a microphone port in the cellular telephone. Likewise, the signal received by a cellular telephone can be emitted by either an internal speaker or an external speaker connected to the cellular telephone through a speaker port in the cellular telephone. Cellular telephones transmit and receive information using radio signals and are capable of sending and receiving radio signals in either an analog or digital format. Unfortunately, the signal emitted form the cellular telephone is not encrypted and can be monitored using radio scanners. Furthermore, even if an encrypted signal is sent to a cellular telephone, existing technology does not provide the means for the cellular telephone to decrypt the signal.
Encryption algorithms which ensure that only the intended recipient of an electronic message will access the message are well known. One such method is the asymmetric or public key algorithm described in U.S. Pat. No. 6,169,805 entitled “System and Method of Operation for Providing User's Security on Demand Over Insecure Networks.” The public key algorithm is a method for encrypting electronic messages sent from a first entity to a second entity using a pair of mathematical keys. The algorithm comprises a public key and a private key which are mathematically related such that if the private key is used to encrypt data, then only the matched public key can be used to decrypt the data, and vice-versa. Encryption keys may be obtained form a certificate authority, which is a mutually trusted third party who issues digital certificates. The certificate authority matches the public and private keys to an identity, e-mail address, or similar information provided by the two original parties.
Secured telephone communications are essential to many organizations, particularly the military. Presently however, the preferred method of sending and receiving encrypted data over a cellular telephone is to purchase a telephone which is specifically designed for encrypted communication. Alternatively, separate equipment may be purchased and utilized with conventional cellular telephones in order to transmit and receive encrypted telephone communications. Therefore, a need exists for an apparatus, method, and system to allow a user to encrypt, transmit, receive, and decrypt data on conventional cellular telephone.